cambridge/libs/discordRPC.lua

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local ffi = require "ffi"
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-- Get the host os to load correct lib
local osname = love.system.getOS()
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local discordRPClib = nil
-- FFI requires the libraries really be files just sitting in the filesystem. It
-- can't load libraries from a .love archive, nor a fused executable on Windows.
-- Merely using love.filesystem.getSource() only works when running LOVE with
-- the game unarchived from command line, like "love .".
--
-- The code here setting "source" will set the directory where the game was run
-- from, so FFI can load discordRPC. We assume that the discordRPC library's
-- libs directory is in the same directory as the .love archive; if it's
-- missing, it just won't load.
local source = love.filesystem.getSource()
if string.sub(source, -5) == ".love" or love.filesystem.isFused() then
source = love.filesystem.getSourceBaseDirectory()
end
if osname == "Linux" then
discordRPClib = ffi.load(source.."/libs/discord-rpc.so")
elseif osname == "OS X" then
discordRPClib = ffi.load(source.."/libs/discord-rpc.dylib")
elseif osname == "Windows" then
-- I would strongly advise never touching this. It was not trivial to get correct. -nightmareci
ffi.cdef[[
typedef uint32_t DWORD;
typedef char CHAR;
typedef CHAR *LPSTR;
typedef const CHAR *LPCSTR;
typedef wchar_t WCHAR;
typedef WCHAR *LPWSTR;
typedef LPWSTR PWSTR;
typedef const WCHAR *LPCWSTR;
static const DWORD CP_UTF8 = 65001;
int32_t MultiByteToWideChar(
DWORD CodePage,
DWORD dwFlags,
LPCSTR lpMultiByteStr,
int32_t cbMultiByte,
LPWSTR lpWideCharStr,
int32_t cchWideChar
);
int32_t WideCharToMultiByte(
DWORD CodePage,
DWORD dwFlags,
LPCWSTR lpWideCharStr,
int32_t cchWideChar,
LPSTR lpMultiByteStr,
int32_t cbMultiByte,
void* lpDefaultChar,
void* lpUsedDefaultChar
);
DWORD GetShortPathNameW(
LPCWSTR lpszLongPath,
LPWSTR lpszShortPath,
DWORD cchBuffer
);
]]
local originalWideSize = ffi.C.MultiByteToWideChar(ffi.C.CP_UTF8, 0, source, -1, nil, 0)
local originalWide = ffi.new('WCHAR[?]', originalWideSize)
ffi.C.MultiByteToWideChar(ffi.C.CP_UTF8, 0, source, -1, originalWide, originalWideSize)
local sourceSize = ffi.C.GetShortPathNameW(originalWide, nil, 0)
local sourceWide = ffi.new('WCHAR[?]', sourceSize)
ffi.C.GetShortPathNameW(originalWide, sourceWide, sourceSize)
local sourceChar = ffi.new('char[?]', sourceSize)
ffi.C.WideCharToMultiByte(ffi.C.CP_UTF8, 0, sourceWide, sourceSize, sourceChar, sourceSize, nil, nil)
source = ffi.string(sourceChar)
discordRPClib = ffi.load(source.."/libs/discord-rpc.dll")
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else
-- Else it crashes later on
error(string.format("Discord rpc not supported on platform (%s)", osname))
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end
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ffi.cdef[[
typedef struct DiscordRichPresence {
const char* state; /* max 128 bytes */
const char* details; /* max 128 bytes */
int64_t startTimestamp;
int64_t endTimestamp;
const char* largeImageKey; /* max 32 bytes */
const char* largeImageText; /* max 128 bytes */
const char* smallImageKey; /* max 32 bytes */
const char* smallImageText; /* max 128 bytes */
const char* partyId; /* max 128 bytes */
int partySize;
int partyMax;
const char* matchSecret; /* max 128 bytes */
const char* joinSecret; /* max 128 bytes */
const char* spectateSecret; /* max 128 bytes */
int8_t instance;
} DiscordRichPresence;
typedef struct DiscordUser {
const char* userId;
const char* username;
const char* discriminator;
const char* avatar;
} DiscordUser;
typedef void (*readyPtr)(const DiscordUser* request);
typedef void (*disconnectedPtr)(int errorCode, const char* message);
typedef void (*erroredPtr)(int errorCode, const char* message);
typedef void (*joinGamePtr)(const char* joinSecret);
typedef void (*spectateGamePtr)(const char* spectateSecret);
typedef void (*joinRequestPtr)(const DiscordUser* request);
typedef struct DiscordEventHandlers {
readyPtr ready;
disconnectedPtr disconnected;
erroredPtr errored;
joinGamePtr joinGame;
spectateGamePtr spectateGame;
joinRequestPtr joinRequest;
} DiscordEventHandlers;
void Discord_Initialize(const char* applicationId,
DiscordEventHandlers* handlers,
int autoRegister,
const char* optionalSteamId);
void Discord_Shutdown(void);
void Discord_RunCallbacks(void);
void Discord_UpdatePresence(const DiscordRichPresence* presence);
void Discord_ClearPresence(void);
void Discord_Respond(const char* userid, int reply);
void Discord_UpdateHandlers(DiscordEventHandlers* handlers);
]]
local discordRPC = {} -- module table
-- proxy to detect garbage collection of the module
discordRPC.gcDummy = newproxy(true)
local function unpackDiscordUser(request)
return ffi.string(request.userId), ffi.string(request.username),
ffi.string(request.discriminator), ffi.string(request.avatar)
end
-- callback proxies
-- note: callbacks are not JIT compiled (= SLOW), try to avoid doing performance critical tasks in them
-- luajit.org/ext_ffi_semantics.html
local ready_proxy = ffi.cast("readyPtr", function(request)
if discordRPC.ready then
discordRPC.ready(unpackDiscordUser(request))
end
end)
local disconnected_proxy = ffi.cast("disconnectedPtr", function(errorCode, message)
if discordRPC.disconnected then
discordRPC.disconnected(errorCode, ffi.string(message))
end
end)
local errored_proxy = ffi.cast("erroredPtr", function(errorCode, message)
if discordRPC.errored then
discordRPC.errored(errorCode, ffi.string(message))
end
end)
local joinGame_proxy = ffi.cast("joinGamePtr", function(joinSecret)
if discordRPC.joinGame then
discordRPC.joinGame(ffi.string(joinSecret))
end
end)
local spectateGame_proxy = ffi.cast("spectateGamePtr", function(spectateSecret)
if discordRPC.spectateGame then
discordRPC.spectateGame(ffi.string(spectateSecret))
end
end)
local joinRequest_proxy = ffi.cast("joinRequestPtr", function(request)
if discordRPC.joinRequest then
discordRPC.joinRequest(unpackDiscordUser(request))
end
end)
-- helpers
local function checkArg(arg, argType, argName, func, maybeNil)
assert(type(arg) == argType or (maybeNil and arg == nil),
string.format("Argument \"%s\" to function \"%s\" has to be of type \"%s\"",
argName, func, argType))
end
local function checkStrArg(arg, maxLen, argName, func, maybeNil)
if maxLen then
assert(type(arg) == "string" and arg:len() <= maxLen or (maybeNil and arg == nil),
string.format("Argument \"%s\" of function \"%s\" has to be of type string with maximum length %d",
argName, func, maxLen))
else
checkArg(arg, "string", argName, func, true)
end
end
local function checkIntArg(arg, maxBits, argName, func, maybeNil)
maxBits = math.min(maxBits or 32, 52) -- lua number (double) can only store integers < 2^53
local maxVal = 2^(maxBits-1) -- assuming signed integers, which, for now, are the only ones in use
assert(type(arg) == "number" and math.floor(arg) == arg
and arg < maxVal and arg >= -maxVal
or (maybeNil and arg == nil),
string.format("Argument \"%s\" of function \"%s\" has to be a whole number <= %d",
argName, func, maxVal))
end
-- function wrappers
function discordRPC.initialize(applicationId, autoRegister, optionalSteamId)
local func = "discordRPC.Initialize"
checkStrArg(applicationId, nil, "applicationId", func)
checkArg(autoRegister, "boolean", "autoRegister", func)
if optionalSteamId ~= nil then
checkStrArg(optionalSteamId, nil, "optionalSteamId", func)
end
local eventHandlers = ffi.new("struct DiscordEventHandlers")
eventHandlers.ready = ready_proxy
eventHandlers.disconnected = disconnected_proxy
eventHandlers.errored = errored_proxy
eventHandlers.joinGame = joinGame_proxy
eventHandlers.spectateGame = spectateGame_proxy
eventHandlers.joinRequest = joinRequest_proxy
discordRPClib.Discord_Initialize(applicationId, eventHandlers,
autoRegister and 1 or 0, optionalSteamId)
end
function discordRPC.shutdown()
discordRPClib.Discord_Shutdown()
end
function discordRPC.runCallbacks()
discordRPClib.Discord_RunCallbacks()
end
-- http://luajit.org/ext_ffi_semantics.html#callback :
-- It is not allowed, to let an FFI call into a C function (runCallbacks)
-- get JIT-compiled, which in turn calls a callback, calling into Lua again (e.g. discordRPC.ready).
-- Usually this attempt is caught by the interpreter first and the C function
-- is blacklisted for compilation.
-- solution:
-- "Then you'll need to manually turn off JIT-compilation with jit.off() for
-- the surrounding Lua function that invokes such a message polling function."
jit.off(discordRPC.runCallbacks)
function discordRPC.updatePresence(presence)
local func = "discordRPC.updatePresence"
checkArg(presence, "table", "presence", func)
-- -1 for string length because of 0-termination
checkStrArg(presence.state, 127, "presence.state", func, true)
checkStrArg(presence.details, 127, "presence.details", func, true)
checkIntArg(presence.startTimestamp, 64, "presence.startTimestamp", func, true)
checkIntArg(presence.endTimestamp, 64, "presence.endTimestamp", func, true)
checkStrArg(presence.largeImageKey, 31, "presence.largeImageKey", func, true)
checkStrArg(presence.largeImageText, 127, "presence.largeImageText", func, true)
checkStrArg(presence.smallImageKey, 31, "presence.smallImageKey", func, true)
checkStrArg(presence.smallImageText, 127, "presence.smallImageText", func, true)
checkStrArg(presence.partyId, 127, "presence.partyId", func, true)
checkIntArg(presence.partySize, 32, "presence.partySize", func, true)
checkIntArg(presence.partyMax, 32, "presence.partyMax", func, true)
checkStrArg(presence.matchSecret, 127, "presence.matchSecret", func, true)
checkStrArg(presence.joinSecret, 127, "presence.joinSecret", func, true)
checkStrArg(presence.spectateSecret, 127, "presence.spectateSecret", func, true)
checkIntArg(presence.instance, 8, "presence.instance", func, true)
local cpresence = ffi.new("struct DiscordRichPresence")
cpresence.state = presence.state
cpresence.details = presence.details
cpresence.startTimestamp = presence.startTimestamp or 0
cpresence.endTimestamp = presence.endTimestamp or 0
cpresence.largeImageKey = presence.largeImageKey
cpresence.largeImageText = presence.largeImageText
cpresence.smallImageKey = presence.smallImageKey
cpresence.smallImageText = presence.smallImageText
cpresence.partyId = presence.partyId
cpresence.partySize = presence.partySize or 0
cpresence.partyMax = presence.partyMax or 0
cpresence.matchSecret = presence.matchSecret
cpresence.joinSecret = presence.joinSecret
cpresence.spectateSecret = presence.spectateSecret
cpresence.instance = presence.instance or 0
discordRPClib.Discord_UpdatePresence(cpresence)
end
function discordRPC.clearPresence()
discordRPClib.Discord_ClearPresence()
end
local replyMap = {
no = 0,
yes = 1,
ignore = 2
}
-- maybe let reply take ints too (0, 1, 2) and add constants to the module
function discordRPC.respond(userId, reply)
checkStrArg(userId, nil, "userId", "discordRPC.respond")
assert(replyMap[reply], "Argument 'reply' to discordRPC.respond has to be one of \"yes\", \"no\" or \"ignore\"")
discordRPClib.Discord_Respond(userId, replyMap[reply])
end
-- garbage collection callback
getmetatable(discordRPC.gcDummy).__gc = function()
discordRPC.shutdown()
ready_proxy:free()
disconnected_proxy:free()
errored_proxy:free()
joinGame_proxy:free()
spectateGame_proxy:free()
joinRequest_proxy:free()
end
return discordRPC